Baccano!

In 1711, a group of alchemists seeking eternal life gathered on a boat to summon the "demon" that held the secret. The demon agreed to give them what they wanted—an elixir of life, the method to create more, and the secret to ending their new-found existence. The following night, alchemists began disappearing, "eaten" by one of their own. Realizing the threat being close together posed, they decided to scatter across the world. Centuries later, in Prohibition-era America, the immortals have come together once again, and the "stupid commotion" (baccano) starts.

Welcome to Ikebukuro, where Tokyo's wildest characters gather!! Meet an ordinary boy who daydreams about the extraordinary. A naive stalker girl. The strongest man in Ikebukuro. A shut-in doctor with questionable credentials. A hedonistic informant...and the "headless rider" astride a pitch-black motorcycle!? As their paths cross, this eccentric cast weaves a twisted, cracked love story... (Source: Yen Press)

In 1705, a rash of murders takes place in Lotto Valentino, a provincial city on the Italian peninsula. The murderer, who wears a pure white mask and places one such mask on all of their victims, is known as the "Mask Maker," and anyone who witnesses their murders becomes their next victim. Huey Laforet, a boy who attends a "private school" for alchemy, hates everything about the world. Monica Campanella, his schoolmate, confesses her feelings for him. Elmer C. Albatross arrives in town as the school's newest student. Niki, a merchant's slave girl, witnesses one of the Mask Maker's crimes. All four youths must confront the Mask Maker and a conspiracy to control the entire city — the start of a 300-year-long struggle amongst immortals.

Aboard the Advenna Avis in 1711, a group of alchemists summon a demon in the hopes of gaining eternal life. The demon gives them an elixir of immortality and the method of ending their existence by "devouring" one another. Soon after, one among them begins to devour his companions. Realizing the danger posed by staying together, they scatter across the globe. Centuries later in 1930's America, a certain federal investigator tries his best to combat the rise of organized crime during Prohibition, send a particularly infuriating terrorist to Alcatraz, and catch an outrageous thief duo. Meanwhile, the transcontinental train, the Flying Pussyfoot, begins its trail of blood across the country. In 2002, a small group of the original Advenna Avis alchemists are on a journey to find the rest of their fellow immortals. However, there is one companion they did not expect to meet again. Seemingly unrelated events, from a sleepy Italian city in the early 1700's to a modern luxury cruise ship traveling across the Pacific, reveal themselves to be far more connected than anyone could imagine... (Source: Wikipedia & MAL Rewrite)